Sparks Fly (Sequel)
by Mrs.Becker
Summary: Katherine "Catalyst" Harper is Tony's girlfriend and she is the owner of Harper Energy. In a terrible accident at her factory Katherine's body absorbed energy turning her into a powerful source. She has become an object that can supply half the world with power. When Agent Coulson come to Tony and Kat for help it takes all she has to control the dangerous powers she has been given.
1. Chapter 1

**This is the lovely continuation of my one shot also called Sparks Fly hope you enjoy the rest of Katherine Harper's story.**

**Sparks Fly**

**Chapter 1**

"Hey Ironman are you sure you can get this one?" I asked spinning around in a chair.

"If set foot in the water the whole ocean would be electrified," Tony spoke through the suit. Currently Tony was in the ocean cutting a pipeline transport with a laser cutter from the suit. "You're good on this end. The rest is up to you," Tony said as he shot up out of the water and towards Pepper and I at Stark tower.

"You disconnected the transition lines? Are we off the grid?" Pepper asked Tony.

"Stark Tower is about to become a beacon of self sustaining clean energy," Tony replied as I scoffed slightly. "Oh, the great Harper is is jealous I did it first?" Tony teased.

"I can power the city with my body alone," I teased back.

"Light up the tower Pepper," Tony ordered as I walked over to Pepper.

"How does she look Tony?" I asked as Pepper light up the tower.

"Like you, but with me. . .me," He said as I laughed.

"Nothing will ever be as beautiful as me," I said as he laughed. "You saying I'm not beautiful?" I asked with a smirk.

"Yeah me," Stark replied as Pepper cleared her throat.

"Gotta go wider on the public awareness campaign. You need to do some press. I can do some more tomorrow. I'm working on the zoning for the next billboards," Pepper said and Tony groaned.

"Pepper, you're killing me. Let's all just enjoy the moment," Tony said as I retrieved the champagne.

"Well get in here and have a toast with us," I said handing Pepper a glass. Tony arrived walking down his landing space as machines grabbed pieces of his suit.

After the toast Pepper left to go home to her husband leaving Tony and I alone. "So how would you like to celebrate this grand achievement?" I asked walking over to Tony my hips swaying from side to side.

"I would love for you to put on that little outfit we bought the other day while I grab us some strawberries and sugar, then we can have fun all night long," Tony replied pulling me into him lightly kissing my neck.

"Sir, Agent Coulson of SHIELD is on the line," JARVIS spoke making Tony and I pull apart.

"I'm not in. I'm actually out," Tony said pressing his lips against mine.

"Sir, I'm afraid he's insisting," JARVIS said as Tony sighed.

"Close the line JARVIS. I got a date," Tony said pulling me out of the room and driving over to Tony's penthouse for our date.

"The energy levels look good," I smiled looking at the monitors.

"Of course they do, I directly involved," Tony said as I stuck my tongue out at him.

"I believe Pepper gets credit as well it was her idea," I laughed as Tony poured us some champagne.

"I'll give her some credit, but lets not talk about that lets talk about this outfit right here," Tony said pulling up the box holding the blue lace teddy.

"Well we could just forget about the outfit and I could get completely naked right her," I whispered my voice husky as he pulled me into his arms.

"Sir, the telephone. I'm afraid my protocols are being overwritten," JARVIS said interrupting us again.

"Sark, we need to talk," Agent Coulson said over Tony's phone.

"You have reached the life model decoy of Tony Stark, please leave a message," Tony said picking up his phone and looking into it at Coulson.

"This is urgent," Coulson said not falling for Tony's trick.

"Then leave urgently," Tony said just as the elevator door opens and Coulson walks out. "Security breach, that's on Pepper."

"Mr. Stark," Coulson nodded as I pulled completely away from Tony to look at the agent.

"Hello Phil good to see you again," I smiled over at him.

"Phil? Uh, his first name is Agent," Tony said jealousy showing in his voice.

"We are celebrating Phil," I said exaggerating his name.

"Which is why you can't stay," Tony said motioning to the elevator.

"We need you to look this over. Soon as possible," Phil said holding a file out to Tony.

"I don't like being handed things. You can get her to look over it," Tony said gesturing to me.

"Fine," I said grabbing the file and handing Phil my champagne glass. "Thank you I smiled before handing the file to Tony.

"Official consulting hours are between eight and five every other thursday," Tony said as Phil still stood there.

"This isn't a consultation," Phil said with a nodded.

"Is this about The Avengers?" I asked grabbing the file back.

"Avengers Initiative was scrapped, I thought. And I didn't qualify, you did though," Tony said sipping his champagne.

"Really?" I asked with a laugh.

"Yeah, apparently I'm volatile, self obsessed, don't play well with other."

"That all seems correct to me," I smiled as Tony scoffed.

"This isn't about personality profiles anymore," Coulson said nodding towards the file.

"Whatever. Miss Harper, got a minute?" Tony asked. I walked over handing Tony the file so he could place it in his database.

"You know I thought we were having a moment," Tony said looking over my face.

"We were but this could be fun Tony, and really, really sexy," I said huskily biting my lip. "Beside's this seems pretty serious," I added as Tony expanded his arms and different profiles appeared in holographic form floating in the air in front of Tony and I.

"This is uh. . . This is," Tony started as Captain America appeared on screen, then Hulk roaring, Thor fighting, and the last one of a strange man and a strange object, which I stared in awe at.

"Phil I'm working on this as well," I told him before he left Tony and I to do our work.

"Work hard Pepper Kat and I will be fine," Tony said into the phone to Pepper who was currently in Washington.

"Tell Pepper I love her," I called out as Tony and I were getting ready to go to Germany where the rest of the Avengers were.

"Kat says she loves you, see you when this is all over oh and Pepper I'd rather you stay safe in Washington so don't come home early," Tony said as the machine place the Iron suit around him. I stripped off my clothes pulling on my specialized outfit made of an energy withstanding cloth. The top was simple and crossed over my chest and the skirt was similar to the top. They both just covered the delicate areas for when I transform back.

"You are looking delicious," Tony smiled kissing me.

"Well we can have this fun later," I smiled placing his mask over his face.

"Fine let's get this over with," Tony said before taking off from the open area, I quickly followed suit changing forms and quickly catching up with Tony.


	2. Chapter 2

**Sparks Fly**

**Chapter 2**

Tony and I flew across the sky heading towards the commotion in Germany. Natasha was flying the Quinjet while Captain America was on the ground fought Loki on the ground.

"This guy's all over the place," I heard Natasha say through the mic placed in my ear. Suddenly, AC/DC's "Shoot to Thrill" blasts through the Quinjet's speakers.

"Agent Romanoff, Did you miss me?" Tony Asked as we flew up onto the seen. Both Captain America and Loki looked to the sky as Tony flew right over them blasting Loki directly in the chest I landed softly on the ground next to Captain America. Ironman touches down standing up then pulling out every piece of weaponry that the suit has. "Make your move, Reindeer Games," Tony said as I stepped out towards Loki looking over him. Loki put his hands up in surrender, his armor dematerializing away.

"You made the best choice," I said returning back to human form.

"Mr. Stark, Ms. Harper," Captain greeted.

"Captain," Tony and I greeted back.

We sat in the Quinjet, Natasha watching the sky as we were jetting in the back. Thunder sounds from nowhere and Fury comes on the headset. "Said anything?" Fury asked.

"Not a word," Natasha replied.

"Just get him here. We're low on time?" Fury said ending the call. Loki was tied and handcuffed to the seat across from me as I sat next to Tony.

"I don't like it," Steve said scrunching his face a little.

"What? Rock of Ages giving up so easily?" Tony asked as I shook my head.

"I don't remember it being ever that easy. This guy packs a wallop," Steve continued.

"Still, you are pretty spry, for an older fellow. What's your thing? Pilates?" Tony asked trying to be funny.

"Tony, sweetie I don't think he understands you," I smiled as Steve smiled back.

"It's like calisthenics. You might have missed a couple things, you know, doing time as a capsicle," Tony explained as I rolled my eyes.

"Fury didn't tell me he was calling you in," Steve said changing the subject.

"Yeah, there's a lot of things Fury doesn't tell you," Tony replied looking away from him. Thunder and lightning strikes barely missing the jet making it shake violently.

"Where's this coming from?" Natasha asked as I readied myself. Thunder rumbles overhead and Loki turns staring out the window.

"What's the matter? Scared of a little lightning?" Steve asked taunting Loki.

"I'm not overly fond of what follows," Loki said lowly.

"Don't worry our resident lightning bolt can handle this electricity," Tony said pointing to me. All of a sudden a blinding light hit the jet, the mighty Thor. Thor opened the ramp and grabs Loki by the throat and flies out. I changed forms as Tony placed his mask back on.

"Now there's that guy," Tony sighed.

"Another Asgardian?" Natasha asked.

"Think the guy's a friendly?" Steve asked as I stepped to the opening.

"Doesn't matter. If he frees Loki or kills him, the Tesseract's lost," Tony said as he gets ready to jump off the Jet with me.

"Stark, Harper, we need a plan of attack!" Steve yelled out to us.

"Yeah, attack," I said jumping off the jet and flying after the two figures.

"You listen well, brother. I. . ," Thor started but Tony flew in a took him down as I landed in front of Loki.

"I'm listening," Loki taunts to his brother as I jumped towards him grabbing him and flying him back to the jet.

"Stay," I ordered leaving the jet quickly leaving Loki for Natasha to watch. I flew off to Tony who was fighting Thor in the woods.

I moved to stand in front of Tony as Thor swung his hammer, summoning a ray of energy. I hold out my hands awaiting the arrival of the blast, Thor shoots the blast directly at me, sliding me back into Tony as I absorb the blast into my body. The smoke cleared revealing me standing straight and tall, Thor stared wide eyed as I bring the energy back into a blast and send him to his knees. "My turn baby doll," Tony said s he and Thor fly towards each other. The two battled, Tony grabbing Thor, elbowing him and smashing him into the side of the mountain. Thor leaps off the mountain and takes Ironman with him. Thor and Ironman crashed right back down into the trees in front of me. Ironman yanked Thor right up, Thor grabs both hand boosters and begins crushing them. Tony quickly charges as much energy as he can and shoots energy in Thor's face. Thor fall's back, losing his stance. Ironman headbutts Those, with his gold-titanium alloy helmet. Thor headbutts him back with his head and sends tony cross the forest. Tony flies back but before he could send his hand blasters back at Thor I stood between them causing to stop.

"That's enough," I said sharply looking between them.

"Now, I don't know what you plan on doing here," Steve said as he walked over to us from his landing point.

"I've come here to put an end to Loki's schemes!" Thor yelled back at Steve.

"The prove it! Put the Hammer down," Steve says as Tony shakes his head.

"Um, yeah no! Bad call! He loves his hammer!" Tony yelled. Thor backhands Tony with his hammer. Thor then raises his Hammer at Capt.

"You want me to put the hammer down?" Thor asked before leaping into the air, raising the hammer. Capt. crouches down and holds up his shield. Thor brings the hammer down onto the shield and a massive implosion of light reacts to the vibranium shield creating a massive shockwave that blew us all over.

Tony and I stand up, looking around at the damage. Thor looks between all of us still shocked. "Are we done here?" Steve asked as we all just stood silent.

Tony and I arrive on the SHIELD ship where we both started reading books filled with information about thermonuclear astrophysics. "My little Catalyst remind me why we are reading text books and not having sweet dirty sex?" Tony asked looking up from his book.

"Save the world first then sex," I smiled throwing the finished book to the side.

"Or, hear me out we have sex right hear surrounded by these books and we can just absorb the knowledge by slight skin contact and then read the rest after," Tony said as he pushed some books to the side. I smiled pushing mine to the side meeting him halfway.

"You think I'm that easy?" I asked hovering my lips over his.

"When it comes to me, yeah," Tony said before crashing his lips into mine causing us to fall back onto the ground in front of our bed.


	3. Chapter 3

**Sparks Fly**

**Chapter 3**

Tony and I walking with Agent Coulson to the meeting room. "Rome is very nice, hardly visited any of the sites though," I explained to Coulson who was asking us about our recent international trip.

"Yeah it was quite beautiful from the hotel window," Tony added with a smirk as we walked into the room.

"Iridium, what did they need the Iridium for?" I heard Dr. Banner ask upon entry.

"It's a stabilizing agent," Tony answered before turning back to Coulson, "I'll fly you there. Keep the love alive." He finished before turning back to the group.

"Iridium will keep the portal from collapsing in on itself, like it did at shield," I explained for Tony as he turned to Thor.

"No hard feelings, Point Break. You've got a mean swing," Tony told him as I rolled my eyes. "Also, it means the portal can open as wide, and stay open as long, as Loki wants," Tony explained going back to the Iridium. Tony looked around the room before speaking to the crew, "Uh, raise the mid-mast, ship the top sails. That man is playing Galaga! Thought we wouldn't notice. But we did," Tony ranted then covered one of his eyes, "How does Fury do this?" He asked looking around.

"He turns," Agent Hill answered. Tony looked around at the monitors and placed a button sized hacking implant under Fury's desk which I only noticed.

"Well, that sounds exhausting," Tony said giving me a wink.

"Everything else that is need Agent Barton can get his hands on easily but the last thing he needs is a power source. A high energy density, something to kick start the cube," I finished explaining.

"When did you two become experts in thermonuclear astrophysics?" Agent Hill asked.

"Last night. The packet, Selvig's notes, the Extraction Theory papers. Are we the only ones that did the reading?" Tony asked looking at everyone.

"Does Loki need any particular kind of power source?" Steve asked.

"He's got to heat the cube to a hundred and twenty million Kelvin just to break through the coulomb barrier," Dr. Banner explained to Steve.

"I alone have the ability to do that," I piped in.

""Unless, Selvig has a figure out how to stabilize the quantum tunneling effect, if not he would have to kidnap her and force her to use her energy which in the end would burn her alive," Tony explained.

"Well, if he could stabilize, he could achieve Heavy Ion Fusion at any reactor on the planet," Dr. Banner added.

"Finally, someone who speaks English," Tony said looking at Dr. Banner as I raised an eyebrow. "Of course you also speak English my little Catalyst," Tony added as I nodded my head sarcastically.

"Is that what just happened?" Steve asked confused. Dr. Banner walked over to Tony and I and shakes Tony's hand giving each other a look of mutual respect.

"It's good to meet you, Dr. Banner. You're work on anti-electron collisions is unparalleled. And I'm a huge fan of the way you lose control and turn into an enormous green rage monster," Tony greeted.

"Tony thats rude some people can't help lab accidents," I said as Dr. Banner shook my hand. "Hi, Katherine Harper but you can call me Kat I am known as the Catalyst," I introduced.

"Yeah I remember the lab accident with the clean energy your body absorbed it and now you can produce energy to sustain the word," Dr. Banner said acknowledging my work.

"Dr. Banner is only here to track the cube. I was hoping you two might join him," Nick Fury said as he walked into the room.

"Let's start with that stick of his. It may be magical, but it works an awful lot like a Hydra weapon," Steve said as I looked over at him.

"I don't know about that, but it is powered by the cube. And i'd like to know how Loki used it to turn two of the sharpest men I know into his personal flying moneys," Fury stated.

"Monkeys? I don't understand," Thor said speaking up.

"I do! I understood that reference," Steve said excitedly as Tony rolled his eyes at him.

"Come on boys lets go play," I said to Tony and Dr. Banner before walking out of the room to the lab.

I sat on a stool in the lab in front of a board full of algorithms, I spun around on the stool before facing to algorithm again. Something was off and I couldn't place what was making my work incorrect.

"What is she doing?" Dr. Banner asked Tony.

"She is thinking, when she is stuck on a problem moving helps the gears turn again, it's like it wastes some of the pent up energy so she can focus again, soon enough she will erase the whole thing and start over coming up with the correct solution," Tony said from in front of his own algorithm.

"I have it," I squealed before erasing the board and quickly righting down the correct equation. Tony smiled at me as a few sparks popped in the air. Dr. Banner scanned the scepter with the gamma ray detection device as I walked over to him.

"the Gamma readings are definitely consistent with Selvig's reports on the Tesseract. But it's gonna take weeks to process," Dr. Banner spoke up.

"If we bypass their mainframe and direct a reroute to the Homer Cluster we can clock this around six hundred teraflops," Tony said looking up from his monitors.

"All I packed was a tooth brush," Dr. Banner admitted making me laugh.

"You know, you should come by Stark Tower sometime. Top ten floors, all R&D. You'd love it, it's candy land for people like her and I," Tony said with a smile.

"Thanks, but the last time I was in New York I kind of broke. . . Harlem," Banner admitted sheepishly.

"Don't worry if taking all the power from New York several times," I told him to make him feel better.

"Well, I promise a stress free environment. No Tension. No surprises," Tony said as I scoffed. Tony suddenly poked banner with a mini-electrical prod just as Steve walked in.

"Ow!" Banner yelped touching his side as Tony looked closely at Banner.

"Hmmm, nothing," Tony said still looking at him closely.

"Hey! Are you nuts?" Steve asked looking at them.

"Relax Steve he is only joking, if something so simple set off Dr. Banner do you really think he would be here?" I asked but Steve completely ignored me.

"You really have got a lid on it, haven't you? Mellow jazz? Bongo drums? Huge bag of weed?" Tony asked Dr. Banner.

"Is everything a joke to you?" Steve asked stepping closer to them.

"Funny things are," Tony replied with a smirk.

"Threatening the safety of everyone on this ship isn't funny. No offense, doctor," Steve said as I stood up from my leaning position.

"Dr. Banner may not take offense to it but I do, it's not like her would purposely cause us to fall out of the sky but it is much easier for me to do it," I said as my eyes began to glow and my hands lit up. "A person who has suffered for as long as he has knows what to do in a situation, how do we even know the soldier who woke up after centuries of sleeping in ice isn't destructive?" I asked my voice raising with each word and the glow spreading throughout my body.

"Woah, it's alright. I wouldn't have come aboard if I couldn't handle pointy things," Dr. Banner spoke up trying to get us both to calm down but anger was building up inside my body.

"You're tiptoeing big man you need to strut," Tony said to him and I kneeled on the ground. The staff started to glow brighter from it's position as they all turned towards my kneeling from.

"Kat? Hey sweetie don't worry just some grown ups arguing no need to kill us," Tony said as he moved to my said.

"I can't. . . it's not me," I said through gritted teeth.

"What do you mean it isn't you?" Steve asked backing away from me.

"It's the staff! It's glowing as brightly as her," Dr. Banner said but just as Tony turned to look at it everything stopped my energy dispersed like it was never there and the staff returned to normal.


End file.
